package com.hmdp.utils;

import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock{
    private StringRedisTemplate stringRedisTemplate;
    private String name;

    public SimpleRedisLock(StringRedisTemplate stringRedisTemplate, String name) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.name = name;
    }

    private  static final String KEY_PREFIX = "lock:";
    private  static final String ID_PREFIX = UUID.randomUUID().toString(true)+"-";
    private  static  final DefaultRedisScript<Long> UNLOCK_SCRIPT ;
    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setResultType(Long.class);
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
    }
    //创建锁
    @Override
    public boolean tryLock(long timeoutSec) {
        //获取线程id
        String value = ID_PREFIX + Thread.currentThread().getId();
        //获取锁
        Boolean success = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, value, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);
    }


    //释放锁
    @Override
    public void unlock() {
        stringRedisTemplate.execute(UNLOCK_SCRIPT, Collections.singletonList(KEY_PREFIX+name),ID_PREFIX+Thread.currentThread().getId());
    }
//    @Override
//    public void unlock() {
//        String value = ID_PREFIX + Thread.currentThread().getId();
//        String redisValue = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//        if(value.equals(redisValue)){
//            //释放锁
//            stringRedisTemplate.delete(KEY_PREFIX + name);
//        }
//    }
}
